Integrated process for the production of antioxidants and dietary fiber from grape pomace

Abstract

The present invention consists of developing an integrated process for the production of antioxidants and dietary fiber from defatted grape pomace dried at 50-60°C to a water content of approximately 6-9% (wet basis). Extraction is optimized by two routes: (i) route 1 allowing the extraction of antioxidants and dietary fiber concentrates with a three-fold extraction in 65% ethanol, according to a mass-volume ratio, m :v, : 1:33, at a temperature of 85-90°C, and an extraction time of 25-30 minutes followed by separation of the liquid and solid phases by centrifugation or another equivalent process, freeze-drying of the filtrate allows obtaining a powder rich in antioxidants and drying of the residue allows obtaining a fibro-protein concentrate; (ii) Route 2 involves hot water extraction of antioxidants followed by separation of the liquid and solid phases by centrifugation or another equivalent process, then precipitation of soluble fibers from the filtrate with ethanol, followed by removal of the ethanol from the filtrate and its freeze-drying to obtain an antioxidant-rich powder. Drying and grinding of the recovered residue yields a fiber-protein concentrate (Figure 1).